So I’ve been working through the issues on a 2001 California EV that’s been sitting for about 10 years. Have managed to do most of things needed and have had much useful advice for which I am very grateful!
Link to previous fuel line/ filter/ pressure regulator journey here: California EV running/ throttle issue? - #51 by JeffOdysseus
Now I’m moving on to throttle body balancing and adjusting the TPS. Using a lonelec Italia reader and guzzidiag. I attempted to reset the TPS last night. Was relatively successful but (and this is my question) I could not get the TPS set anywhere below 176mv. It would jump straight to zero. If I went above 176 it would jump straight to 196mv. I’m wondering if anyone has any thoughts on this? I went ahead and set it up at 176 and made the idle adjustment from there. Took out for spin and feels like a different bike! Starts and idles better etc I am still however a bit confused as to why I couldn’t get the base reading down to 150? Is the TPS done for?
Just FYI, when I first plugged it in with everything detached/ idle screw backed off/ connecting rod detached and the butterfly completely closed the reading was 500 MV! Lord only knows what the ECU was thinking about that.
I want to move on to balancing next but I guess I’m wondering should I replace the TPS before I bother to do that?
Any thoughts would be greatly appreciated
Only one brief thought (I’m not expert in setting up the TPS, and my colleague is off today, I’m fairly sure that the reading is non-liner, almost logarithmic.
Perhaps someone else has first hand knowledge of what the ‘normal‘ settings are for the early FI bikes?
As mine is now operational I could try to get my readings, although I’m up to my armpits in Tiger 1050 currently 
Well done for the perseverance so far!
Thanks Jeff. Don’t let me distract you from your tigers! I myself have to move onto a blackbird soon 
. Although I think keeping it off the road generally keeps me and my licence safer!
I have genuinely really enjoyed the process with this guzzy. I found myself doing things I would not attempt on other bikes. And having gone this far it gives me a sense of safety in that I pretty much know it inside out now…. Although if I do any long distance tours I have a feeling my tool kit’s going to take up most of my bag space. Perhaps a bit of knowledge can be a bad thing .
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there is a useful video on ‘this old tractor’
https://www.thisoldtractor.com/moto_guzzi_technical_training_videos_eng_v1100_fuel_system__cylinder_synchronisation_california.html
If your TPSreadings are ‘jumping about’ i would suggest its toast. As you open the Throttle, the TPS readings should be a smooth transition from ‘fully closed’ to ‘fully open’
Hope this helps!
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Thanks Nik that is a really useful video! Best one I’ve seen. Interesting though that a lot of other instructions on setting / checking the TPS initially completely back of the left idle screw and check the TPS with the butterfly fully closed (150 mv) then wind the idle screw in to get a reading of 530mv ± (3.2-3.6° open). I’m trying to bend my mind stuff why you would or wouldn’t bother to set the initial 150 mv fully closed?
My TPS stays stable at 176 mv and remains stable at 530mv. What had me a bit concerned is that the numbers don’t run sequentially when I move it around. They jump i.e 0- 176-196-206 etc. Mostly going up in 10s. I am wondering if this is normal or if it should run perfectly sequentially when being repositioned. So I wonder what other people’s experience is.
You’re probably right that the TPS is toast! Although the bike is super low mileage. I wonder how sitting around doing nothing could degrade the TPS. I’ll probably just try a new one anyways.
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I’ve ordered a cycleworks one for £68, the magneti marelli oem ones seem crazy expensive. The jump from o-176 mv suggests to me that the track is corroded so thought I might as well try a new one….
Link if anyone’s looking for an alternative
Although, maybe let me check it works before buying one
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The fully closed 150Mv setting is a ‘base’ setting which you wouldn’t normally need to use if you are just balancing the Throttle bodies. The time you would need it really is if you can’t set the correct idle when using ‘std’ settings.
I had an EV in the workshop other day that i couldn’t get right. Removed the bodies from the bike and the insides were all gummed up and the butterflys weren’t closing fully. When i’d finished cleaning the TPS was miles out so had to reset it fully closed at 150Mv. Then using std settings the idle and Co were spot on!
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Thanks Nik, I have a feeling that that is the problem here too. Having just put it all back together I’m reluctant to take it all apart again to get the throttle body out and clean it. But it is likely what needs to be done.
The bit I have have found hardest is putting the airbox back in. I’m wondering if you have any advice on that?; I’m thinking to get the throttle body out Perhaps I don’t need to pull it right out. Take the battery out, disconnect the rubbers and pull it backwards?
To get them out i usually remove the Inlet Manifolds and the Airbox Snorkels. Undo all the cables and hoses and then you wiggle them out. Its a bit of a faf but you shouldn’t need to remove the Airbox itself. You can , if you want, just undo one side at a time by unscrewing them from the support Bars but i find getting the 4 screws undone just as much a pain as the other method!
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Ok, so, over the weekend I have had the throttle body out and cleaned it. checked the boots which seem fine and lubricated the throttle cables. I installed the new tps and sadly had exactly the same issue as before. when setting the base setting (150mv ±) i could get it down to 176mv but after that the reading would jump straight to 0. I am a bit mystified and wondering if it is perhaps because i am using Guzzi diag to read the voltage? That said I have trawled the internet and have not found anyone having a similar issue. I am looking for opinions about just setting it there (@176mv). The idle setting is fine and easy to achieve. One thought i have had is that the previous owner may have moved the ‘sacred screw’ on the right throttle body thinking it was an idle adjuster??
A couple of thoughts!
You are disconnecting the Lefthand Link Bar when setting the base TPS setting?
I do mine useing a Multimeter and a Breakout Lead.
Let me try and run thru this step by step!
Disconnect L/H Link Bar and back out L/H ‘sacred screw’ so that it does not touch the Adjuster plate and the butterfly is 0 deg (fully Closed)
Rotate the TPS itself until you achieve 150Mv then useing the L/H ‘sacred screw’ winde it in until you achieve 176Mv (butterfly slightly open) + or - about 15Mv on both
Reconnect Link Bar. Make sure Byepass Screws are 1/2 turn out. Run engine upto temperature. Balance idle using R/H sacred screw. Run engine upto 2500/3000RPM to balance fast running using Adjuster in the middle of the Link Bars (Sometimes on the L/H Throttle Body)
That should give you the correct Idle and CO. If the CO is slightly out you can adjust using Byepass Screws, though you shouldn’t have to! Final setting of Idle, use the Idle Adjuster screw
I hope that all make sense, Nik
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Thanks Nik. Yes that all makes sense.
To answer your question. Yes I have the left throttle body isolated (linkage disconnected, idle screw fully backed out). I’m doing everything as per instructions here:
Brad The Bike Boy: Throttle Position Sensor setting procedure for Moto Guzzi California and Bellagio
Despite that when I try to manipulate the TPS in order to get a base reading of 150mv it goes down to 176mv then jumps to zero. I am using guzzidiag to read the position/voltage. It is as if the ECU will not read below 176mv.
Everything is slack, the throttle bodies have been removed/ cleaned. I don’t think anything is physically stopping anything. To my mind it must be electrical? I am going to try reading the TPS with a multi meter instead of through the ECU to see what reading I get.
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I can’t say i’ve ever had the problem you are having although i use Guzzidiag, i don’t it for setting the TPS/Throttle bodies.
Let me know what happens!
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I’ll let you know how it goes. I think the issue is going to be measuring the voltage using Guzzi diag rather than a multimeter..
Also whilst I was at it I discovered that someone had previously set the CO trim at +126. Basically as high as it would go! Either whilst it was sitting in the garage for 10 years the ECU had gone mad or the previous owner had been in there doing something interesting! The first thing I noticed when I plugged it in was that the TPS was set at 520mv with the butterflies fully closed. Then the co trim maxed out. Makes me think that they were having trouble with it running ( most likely because it had been sitting and the fuel had gone bad in the tank/filter/pump etc) and rather than doing the physical work of going through the fuel system someone attempted to address it with the ECU. Which does make me wonder if perhaps they have meddled with the factory set screw on the right throttle body? How would one know if someone had messed around with that screw?
All of that said, I did take it out for a ride last night and it is running infinitely better than it was! I reset the CO trim to zero and did get a few misfires at low revs. I have upped the CO trim to plus 10 now and we’ll see how that goes next time I’m out.
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Sounds like you’ve had a long, but fruitful, journey getting the old girl running, but so much accumulated knowledge in the process! Fair play to you for the perseverance 
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Thanks Jeff, yes it has been a learning curve! I have really enjoyed it though. To the point that I am actively looking for another one. Although not the same, I was thinking about some sort of late 80s early 90s thumper. Something like a tenere but then someone showed me a picture of a guzzy tt65! So I’m on the hunt for one, it’s perfect because it’s really unlikely that I’ll find one! Thusly I get to fantasise about it but don’t actually have to spend any money!
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Indeed! Something of a rare beasty I believe.
Nice if you can find one though. Italian used market?